I think if people pay £30 to airsoft, they've paid to airsoft as they want...
In terms of 'motivating' people... I don't approve of anybody standing around shouting, yelling, or otherwise trying to bully(!) people into being as active as they feel, deem and demand they be.
My mother is allowed to shout at me, my girlfriend when Ive genuinely done something wrong, but other than that - f*ck off if you think you got some right to yell at me just because you're frustrated at a games progress. Learn to chill.
By all means, calmly explain the importance of pushing up, inform players who can't see the necessity in attacking, educate people why a high tempo is crucial for a win and so on, but if they opt not to heed your words - so be it - leave them to it... That's their prerogative.
There is a difference between trying to lead others, and just being a loud bossy bastard.
New players especially need encouragement, information and support. They are newbies in a sport - not green grunts in anybody's personal LZ.
A good site will know all of this. Their marshals will try and keep games moving themselves, will help players to get stuck in, and vitally - will protect them from the site gob who thinks he's General Patton.